package ocp;
public class Ocp {
    public static void main(String[] args) {
//使用看看存在的问题
        GraphicEditor graphicEditor = new GraphicEditor();
        graphicEditor.drawShape(new Rectangle());
        graphicEditor.drawShape(new Circle());
        graphicEditor.drawShape(new Triangle());
        graphicEditor.drawShape(new OtherGraphic());
    }
}
//这是一个用于绘图的类 [使用方]
class GraphicEditor {
//接收 Shape 对象，调用 draw 方法
    public void drawShape(Shape s) {
        s.draw();
    }
}
//Shape 类，基类
abstract class Shape {
    int m_type;
    public abstract void draw();//抽象方法
}
class Rectangle extends Shape {
    Rectangle() {
        super.m_type = 1;
    }
    @Override
    public void draw() {

        System.out.println("  绘制矩形 ");
    }
}
class Circle extends Shape {
    Circle() {
        super.m_type = 2;
    }
    @Override
    public void draw() {

        System.out.println("  绘制圆形 ");
    }
}
//新增画三角形
class Triangle extends Shape {
    Triangle() {
        super.m_type = 3;
    }
    @Override
    public void draw() {

        System.out.println("  绘制三角形 ");
    }
}
//新增一个图形
class OtherGraphic extends Shape {
    OtherGraphic() {
        super.m_type = 4;
    }
    @Override
    public void draw() {

        System.out.println("  绘制其它图形 ");
    }
}
